Particularly sophisticated precast concrete elements with a length of over 9 m were manufactured for the construction of the mausoleum in remembrance of the Battle of Ostrołęka. The Prefabet Ełk Sp. z o.o. company from Poland took on this challenge. Prefabet Ełk Sp. z o.o . spe- cialises in the production of structural precast concrete elements, pipes and manholes, concrete products and fair-faced concrete elements. In addition the plant also supplies ready-mix and self-compacting concrete. ‘Prefabet Ełk Sp. z o.o.’ started its business activities in the 1997 and is today one of the leading producers of precast concrete elements in the northeast and central part of Poland with 130 employees.